Drill chuck



Patented @et il?, lQZZ.

STATES HERMAN CASLER, OF yCAhl'-ASI.C)TA, NEW YOBLK.`

DRILL CHUCK.

Application filed March 29, '1919. `Serial No. 815,964.

To all whom t may' cof/cern Be it known that I, HERMAN QAsLnR, a citizen of the United States of America, and vresident of Canastota, inthe county of Madison, in the State of New York, have invented new and useful improvements 1n Drill Chucks, of which the following, taken in connection with the accompanying .rawings, is a full, clear, and exact descriptlon.

This invention relates to certain improvements in drill chucks and analogous implements involving the use 'of a cylindrical head having a diametrical'slot or guideway extending from-side to side and 'through the outer end face thereof for receiving radially movable gripping aws whereby the 'tool or work may be tightened and released upon and from the head.

ln chucks of this character' the jaws are preferably operated 'by one or more screws journaled in the side wall ror Walls of vthe slot and engaged with threads in the corresponding side or sides of the j aws'thus causing a greater or less tendency togspring or spread the walls'of the slot and 'particularly when tightening the jaws upon the tool or work.

The main object of my present invention is 'to provide a more efiicient and economical means for iirmly holding the opposite walls of the slot in fixed relation to each other against spreading or springing under all conditions 'than has heretofore. been practced. I l

One of the specific objects is to 'bridge the slot by means of a relatively Ythin circular metal plate secured flatwise to the end face of 'the head by screws or equivalent fastening means, and to provide said plate with opposed ribs or shoulders running lengthn wise of the slot at opposite sides thereof for interlocking engagement with c0mpanion shoulders or abutnients on the adjacent portion of the end face of the head so as to positively resist any tendency of the walls of the slot to spread 0r spring outwardly at points most remote from the base of the slot where the radial thrust .is more appreciable.

A further object is to recess the outer end face of the head in such manner as to receive the ribs on the inner face of the plate and at the same time to assist in centering said plate upon the head when securing it in place.

Other objects and uses relating to specific parts of the head and plate will 'be brought out 'in' the following` description.

In the drawings: Figure l, is an end face view 0f a drill chuck 'embodying the various features of my invention.

:Figure 2, is a longitudinal sectional View tafken on line 2 2 Figure l;

Figure 8, is la perspective view of the depached bridge plate viewed from its inner sic e. As illustrated, this chuck comprises a cylindrical head -lof suitable metal having a diametrical slot -2 extending axially `the greater portion of the length of the head and also extending 'from side to side and through the outer end of said head tol'form a guideway for a pair of opposed radially movable jaws -3-, 'the inner en'd of the head being' 'provided with a central lengthwise 'tapered opening' ladapted to lit upon the usual tapered spindle (not shown) for holding'the headin the machine in which it'is adapted tojbe used.

The opposite walls of the slot are provided near 'the base thereof with llengthwise ribs V-5- adaptedtto enterthe-usual grooves inthe opposite faces ofthe jaws for holding Athe latter against a'Xial displacement in the The jaws *3+ are adapted to be moved simultaneously in `Ythe slot 2 more (in Sthis instance two) screws Q6- which are journaled in suitable bearings -7- in the head 1M .at opposite sides Yof said slot, eachv screw being provided with right hand and left hand threads for engaging the adjacent side of their respective jaws for effecting the simultaneous moveH ment of both jaws in opposite directions,

These screws are necessarily arranged in the opposite walls of the slot *2fbetween the inner and outer ends thereof and parallel therewith, and, therefore, tend to spring said walls apart, particularly when tighten-l ing the jaws upon the work, and in order to obviate this tendency and to firmly hold the outer ends of said walls in iiXed relation under all conditions, I have provided a relatively thin circular bridge plate -8 of substantially the same diameter as the outer end of the head -l to which it is adapted tov be secured flatwise by means of screws 9- as shown in end face view in Figure l.` and by dotted lines in Figure 2.

ln order to relieve the screws --9- from by one or lll() aan een? as shearing strains and to more. firmly hold the opposite walls of the slot in fixed relation,

the plate -8- is p-rovided with a pair of opposed lengthwise ribs 10 running parallel with and at opposite sides of the slot -2- and adapted to enter lengthwise grooves or channels `--ll in the adjacent portions 0f the end 'faces of the head -'-1-. y The channels or `recesses -lland ribs '-'10- are located equal distances from the longitudinal center of the slot Q- and axis olf the head -1 which permits the plate to be reversed side for side and applied to the end face of the head with equal 'facility inr either position, it being understood that the screw holes in the plate and head are arranged lto register with each other in. both positions.

The channels or recesses -llare preterably formed by a rotary cutter and are, therefore, curved about an axis at right an'- gles to that or' the head but parallel with each other, the inner walls oi' the channels 'being sub-stantially parallel with the axis ot' the head to rform abutting shoulders l2-, while the outer walls are preferably beveled or inclined outwardly and axially to facilitate the centering of the bridge plate when applied to the adjacent end of the head.

The ribs -l0- are preferably formed by pressing or striking up portions of the bridge plate beyond the inner i'ace thereof, and thenmilling the inner edges of the ribs in planes parallelv with the longitudinal cen ter of the slot tov form abutting shoulders 13- the same distance apart asthe shoulders #M so that when the plate is applied vto the end face of the head, its shoulders -13- will tit snugly Aagainst the companion shoulders -12- on said head, and thereby lock the walls of theslot against spreading irrespective of the screws -9 In other words, the ribs -13 coacting y with the shoulders -l2- constructed in the manner described, not only reduce to a minimum the shearing strains upon the screws, but also hold the opposite walls Yof the slot in iXed relation irrespective of said screws and enable the plate to be easily and quickly applied to the vhead or removed at will without in any way interfering with the yfree operation of the jaws and their operating means. The'term chuck in addition to its ordi nary meaning is intended to cover the use of reamers and analogous tool holders which are weakened morev or less by transverse slots.`

VVhatI claim is: Y

vIn a drill chuck, the combination of a headV having' a slot extendingdiametrically therethrough from side to side and through one end ot' the head, the open end face of the head being disposed at right angles to its axis Vand provided with 'channels at cpposite sides of and parallel with said slot, the sides of the channels nearest the slot being straight and parallel, a circular plate applied to the open end face'of the head and having portions thereof atl opposite sides ol? its axis provided with ribs having their sides facing each other disposed in planes parallel with the slot in the head and engaged with the corresponding sides of the channels, the depth of said channels and ribs being gradually increased from their ends toward their centers to facilitate the centering of the plate on thehead and screws engaging in yapertures in the plate and head at opposite ends of the channels and ribs for securing the plate to the head.

In witness whereof I have hereunto set my hand this 25th da of March, 1919.

H RMAN CASLER Witnesses:`

HENRY'O. TRAVIS, G. A. STROMBLAD. 

